Abstract: A method for treating produced water in a system for treating wastewater is disclosed. The system includes a reverse osmosis unit for removing dissolved solids. The reverse osmosis unit produces a permeate and concentrate. To reduce the fouling potential of the membranes associated with the reverse osmosis unit and/or to increase membrane lifetime and/or to increase system recovery, at least a portion of the concentrate is recycled and mixed with the wastewater stream at a point upstream of the reverse osmosis unit.

Abstract: An oil or gas recovery process (10) is disclosed where resulting produced water includes silica. The process entails removing silica from the produced water via a two-stage process. In the first stage, magnesium oxide is injected into a Magnesium Dissolution Reactor (18) and mixed with the produced water to dissolve magnesium. Effluent from the Magnesium Dissolution Reactor (18) is directed downstream to a warm lime softener (22) where one or more alkaline chemicals are added to the produced water to raise the pH to approximately 10.0 to 11.5. Here, silica is co-precipitated with magnesium hydroxide and/or adsorbed onto magnesium hydroxide precipitates.

Abstract: A method for treating produced water in a system for treating wastewater is disclosed. The system includes a reverse osmosis unit for removing dissolved solids. The reverse osmosis unit produces a permeate and concentrate. To reduce the fouling potential of the membranes associated with the reverse osmosis unit and/or to increase membrane lifetime and/or to increase system recovery, at least a portion of the concentrate is recycled and mixed with the wastewater stream at a point upstream of the reverse osmosis unit.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: An oil or gas recovery process (10) is disclosed where resulting produced water includes silica. The process entails removing silica from the produced water via a two-stage process. In the first stage, magnesium oxide is injected into a Magnesium Dissolution Reactor (18) and mixed with the produced water to dissolve magnesium. Effluent from the Magnesium Dissolution Reactor (18) is directed downstream to a warm lime softener (22) where one or more alkaline chemicals are added to the produced water to raise the pH to approximately 10.0 to 11.5. Here, silica is co-precipitated with magnesium hydroxide and/or adsorbed onto magnesium hydroxide precipitates.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A method for removing contaminants from an influent wastewater stream includes initially chemically adjusting a pH of the influent wastewater stream to less than about 3.5 or maintaining the pH of the influent stream at less than about 3.5. After initially adjusting or maintaining the pH of the influent wastewater stream, the wastewater is directed to a first reverse osmosis system and contaminants are removed from the wastewater. The wastewater is then directed to a second reverse osmosis where additional contaminants are removed from the wastewater. After the wastewater has been subjected to treatment in the first reverse osmosis system and prior to treatment in the second reverse osmosis system, the pH of the wastewater is adjusted upwardly.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A method for removing contaminants from an influent wastewater stream includes initially chemically adjusting a pH of the influent wastewater stream to less than about 3.5 or maintaining the pH of the influent stream at less than about 3.5. After initially adjusting or maintaining the pH of the influent wastewater stream, the wastewater is directed to a first reverse osmosis system and contaminants are removed from the wastewater. The wastewater is then directed to a second reverse osmosis where additional contaminants are removed from the wastewater. After the wastewater has been subjected to treatment in the first reverse osmosis system and prior to treatment in the second reverse osmosis system, the pH of the wastewater is adjusted upwardly.

Abstract: A wastewater treatment system comprising separation unit operations inhibits or promotes the formation and precipitation of species by controlling the pH of wastewater to be treated entering into the separation unit operations. The separation unit operations include first and second reverse osmosis devices. The first reverse osmosis device treats wastewater having pH that is less than about 3.5 and the second reverse osmosis device treats wastewater, from the first reverse osmosis device, having a pH that is about 6 or higher.

Abstract: A method or process for treating wastewater containing high organics, silica, boron, hardness, and suspended and dissolved solids. The method includes degasifying the wastewater for the removal of dissolved gases and thereafter chemically softening the wastewater. After the chemical softening step, the wastewater is directed through a media filter or membrane which removes additional solids and precipitants. Thereafter the wastewater is directed through a sodium ion exchange that further softens the wastewater. The effluent from the ion exchange is directed through a cartridge filter and the effluent from the cartridge filter is directed through one or more reverse osmosis units. At a selected phase of the process, prior to the wastewater reaching the reverse osmosis unit or units, the pH of the wastewater is raised and maintained such that the pH of the wastewater reaching a reverse osmosis unit is at a pH greater than 10.5.

Abstract: A wastewater treatment system comprising separation unit operations inhibits or promotes the formation and precipitation of species by controlling the pH of wastewater to be treated entering into the separation unit operations. The separation unit operations include first and second reverse osmosis devices. The first reverse osmosis device treats wastewater having pH that is less than about 3.5 and the second reverse osmosis device treats wastewater, from the first reverse osmosis device, having a pH that is about 6 or higher.